Summary of Work: Last year, we analyzed the umbilical cord mercury data and found a statistically significant association between the number of fish meals a mother reported eating a week and her umbilical cord mercury level. We also found a statistically significant relationship between the number of amalgams removed during pregnancy and umbilical cord mercury levels. In the process of analyzing these data, we discovered a pattern in the data that suggested their had been a problem in the laboratory analysis. The samples are being reanalyzed in the laboratory and we will re-do our analysis once the measurements are repeated. Although other researchers have used cord tissue as a biologic monitoring medium for organic mercury, this is the first study to try to use it to measure exposure to mercury vapor during pregnancy. When the data are available we will finish the paper on the relationship between dental treatment during pregnancy and cord mercury levels. This year we plan to analyze the larger cohort for the effect of dental treatment during pregnancy on childhood development.. - umbilical cord, mercury, amalgams, dental, fish consumption, methyl mercury, mercury vapor - Human Subjects: Interview, Questionaires, or Surveys Only